Agricultural irrigation devices are widely utilized for crop irrigation. These irrigation devices normally employ a discharge pipe having a nozzle associated therewith for throwing a stream of water over a field containing a growing crop. To provide the grower with an opportunity to vary the quantity of water, these irrigation devices have sometimes been provided with a set of interchangeable washers which function as discharge orifices for controlling the flow rate through the nozzle. However, systems of this type have proven less than satisfactory since the washer creates a substantial disturbance on the discharged stream of water, whereby the stream does not properly break up, both in terms of particle size and uniformity of dispersion over the irrigation area. These known irrigation nozzles have accordingly not resulted in the necessary uniformity of irrigation, and have often resulted in undesired crop damage.
Accordingly, it is an object of the present invention to provide an improved nozzle assembly for use on an agricultural irrigation apparatus, which nozzle assembly overcomes the above-mentioned shortcomings.
Specifically, it is an object of the present invention to provide an improved nozzle assembly which has a conical nozzle body mountable on the discharge pipe of the irrigation apparatus, which nozzle assembly is also provided with a set of interchangeable tip members of different sizes to permit variation in the flow rate of the nozzle assembly. The individual tip members are all of uniform slope with the nozzle body and have the discharge orifices formed directly at the free ends thereof to ensure that the discharged stream is properly broken up and uniformly dispersed over the irrigation area.
Another object of the invention is the provision of a nozzle assembly, as aforesaid, which can be manufactured in an economical manner, which can be purchased by the grower with minimum cost, which can be readily interchanged while the irrigation apparatus is assembled in the field to provide the desired flow rate, which is of small and compact size, and which provides the grower with a substantially larger selection of different yet relatively similar flow rates so that the grower can provide optimum irrigation.
While it is recognized that nozzle assemblies having removable tip members are well known, as shown in U.S. Pat. Nos. 3,799,453 and 2,225,521, for example, nevertheless none of the known nozzle assemblies employing removable tip members have possessed the features necessary for use on an agricultural irrigation apparatus.
For example, the nozzle assembly shown in above-mentioned U.S. Pat. No. 3,799,453 discloses a tip member wherein the conical flow opening terminates in a discharge orifice which is spaced inwardly a substantial distance from the end face of the tip member, whereby the discharge orifice communicates with a uniform-diameter cylindrical flow passage. This cylindrical flow passage thus acts as a restriction which disrupts the proper discharge of fluid from the nozzle assembly and accordingly prevents the fluid from having the desired breakup and dispersion uniformity necessary for agricultural irrigation. In addition, the nozzle assembly of this patent is designed for use on an irrigation device of the type used for residential purposes, as for sprinkling lawns. Thus, it is not suitable for agricultural irrigation where the discharged stream must be thrown extremely long distances while at the same time provide the desired breakup and uniform dispersion of the water so as to uniformly irrigate the desired area without damaging the crop.